Conventionally, in vehicles, such as automobiles, there may be employed an EGR (exhaust gas recirculation) system in which part of the exhaust gas from an engine mounted on an automobile is recirculated to an intake system and added to a mixed gas in the intake system to lower the combustion temperature of the mixed gas. The employment of this system can reduce the amount of NOx generated.
Further, the regulation of fuels and the prevention of environmental problems demand the reduction of the weight of materials for the above system, and, for meeting such demands, a polyamide resin composition is widely used as a substitute material for a metal (for example, patent document 1).
These materials are required to be further improved in acid resistance.
As a method for improving the acid resistance, patent document 2 proposes a polyamide resin composition comprising a soft fluororesin and a polyamide resin.